Process of preparing 3-carboxymethyl-2-carboxy-chromones

ABSTRACT

2-Carboxymethyl-3-carboxy-chromones and esters of the formula ##STR1## in which R, R 1  and R 2  each independently is hydrogen, an optionally substituted alkyl, alkenyl, cycloalkyl, cycloalkenyl, aralkyl or aryl group, halogen, hydroxyl, cyano or an optionally substituted alkoxy aryloxy, aralkoxy, alkoxy-carbonyl or dialkylamino group, or 
     R and R 1 , together with two carbon atoms of the benzene ring system, form a carbocyclic or heterocyclic 5-membered or 6-membered ring, and 
     R 3  is hydrogen, optionally substituted alkyl, alkenyl, cycloalkyl, cycloalkenyl or aralkyl, 
     are characterized by fungicidal and arthropodicidal activities. The novel compounds are produced by reacting an o-hydroxyacetophenone of the formula ##STR2## with a glyoxylic acid derivative of the formula 
     
         OCH-COOZ 
    
     in which Z is a cation, in the presence of a basic compound, followed by acidification to form the dicarboxylic acid and, optionally, the ester.

This is a continuation of application Ser. No. 039,620, filed May 16,1979, now abandoned, which in turn is a division of application Ser. No.918,129, filed June 22, 1978, now U.S. Pat. No. 4,189,498.

The present invention relates to certain new chromone derivatives, to anunobvious process for their preparation and to their use as plantprotection agents.

It is already known that aromatic aldehydes react witho-hydroxyacetophenones in the presence of sodium hydroxide solution togive 2-phenyl-chromanones (Elderfield, "Heterocyclic Compounds", Vol. 2,page 347); it is also known that aliphatic aldehydes can also be reactedwith o-hydroxyacetophenones to give the corresponding 2-alkylchromanines(see DT-OS (German Published Specification) No. 2,535,338). In bothcases, the o-hydroxyacetophenone and aldehyde react in the molar ratioof 1:1. Further, it is known that chromones can be prepared fromo-acylphenols and carboxylic acid derivatives, again in the ratio of 1:1(see P. Karrer, "Lehrbuch der Organischen Chemie" ("Textbook of OrganicChemistry"), 13th edition, page 584, Georg Thieme Verlag, Stuttgart(1959)).

Zinc ethylene-bis-dithiocarbamate is known as a plant protection agenthaving a fungicidal action, and is recognized as a standard preparationwhich is used worldwide (see R. Wegler, "Chemie der Pflanzenschutz- undSchadlingsbekampfungsmittel" ("Chemistry of Plant Protection Agents andPesticides"), volume 4, page 139, Springer-Verlag, Berlin/Heidelberg/NewYork (1977). However, if low amounts are used, the action is not alwayssatisfactory.

Active compounds which inhibit the metamorphosis of arthropods have onlyin recent times become of interest in plant protection. An example to bementioned here is 2,2-dimethyl-6-methoxybenzopyran (Chem. Eng. News 54,19-20 (1976).

The present invention now provides, as new compounds, the chromonederivatives of the general formula ##STR3## in which R, R¹ and R², whichneed not be identical, each represent hydrogen, an optionallysubstituted alkyl, alkenyl, cycloalkyl, cycloalkenyl, aralkyl or arylgroup, halogen, hydroxy, cyano or an optionally substituted alkoxy,aryloxy, aralkoxy, alkoxycarbonyl or dialkylamino group, or

R and R¹, together with two carbon atoms of the benzene ring system,form a carbocyclic or heterocyclic 5-membered or 6-membered ring and

R³ represents hydrogen or an optionally substituted alkyl, alkenyl,cycloalkyl, cycloalkenyl or aralkyl group.

The compounds of the formula (I) possess fungicidal properties;furthermore, they inhibit the development of arthropods. They aretherefore of interest as plant protection agents.

Preferably, R, R¹ and R², which need not be identical, each representhydrogen, chlorine, bromine, optionally substituted, straight-chain orbranched alkyl with up to 8 (preferably up to 2) carbon atoms (forexample, methyl, ethyl, propyl, isopropyl, tert.-butyl or hexyl),straight-chain or branched alkenyl with one or more double bonds and upto 8 carbon atoms (preferably with up to 3 carbon atoms and one doublebond) (for example, but-3-enyl and 4-methyl-pent-3-enyl), cycloalkyl orcycloalkenyl each with 3 to 8 (preferably with 4 to 6) carbon atoms (forexample cyclobutyl and, especially, cyclopentyl and cyclohexyl), arylwith 6 to 10 carbon atoms (such as naphthyl and, preferably, phenyl),aralkyl of which the aliphatic part contains 1 to 8 (preferably 1 to 4)carbons and of which the aromatic part is a carbocyclic radical with 6to 10 carbon atoms (for example phenylethyl, phenylpropyl, phenylbutyl,naphthylmethyl, naphthylethyl and, preferably, benzyl), alkoxy with upto 4 carbon atoms (such as methoxy, ethoxy, propoxy, isopropoxy, butoxy,isobutoxy and tert.-butoxy), aryloxy with 6 or 10 carbon atoms (such asphenoxy and naphthoxy), aralkoxy with 7 to 10 carbon atoms (such asbenzyloxy, phenylethoxy, phenylpropoxy, phenylisopropoxy, phenylbutoxy,phenylisobutoxy and phenyl-tert.-butoxy), alkoxycarbonyl with up to 4carbon atoms in the alkyl radical (such as methoxycarbonyl,ethoxycarbonyl, propoxycarbonyl and isopropoxycarbonyl), or dialkylaminowith up to 3 carbon atoms in each alkyl radical (such as dimethylamino,diethylamino and diisopropylamino) or wherein the two alkyl radicals ofthe dialkylamino group are cyclized to give a ring (for examplepyrrolidinyl or piperidinyl), the said alkyl, alkenyl, cycloalkyl,cycloalkenyl, aryl, aralkyl, alkoxy, aryloxy, aralkoxy, alkoxycarbonyland dialkylamino groups optionally carrying one or more substituentsselected from fluorine, chlorine, bromine, iodine, cyano, alkoxy with upto 4 carbon atoms, alkoxycarbonyl with up to 4 carbon atoms and, wheresubstituents on ring systems are concerned, also alkyl with up to 4carbon atoms and alkoxycarbonylalkyl with up to 4 carbon atoms, thesubstituted groups optionally carrying, as a further substituent,dialkylamino with a total of up to 6 (preferably up to 2) carbon atoms,carboxyl or phenyl, or R and R¹, with the two carbon atoms of thebenzene ring on which they are located, form a cyclopentene,cyclohexene, benzene, furane, dihydrofurane, thiophene,dihydrothiophene, pyrane, dihydropyrane, pyridine or dioxolene ring.

The invention also provides a process for the preparation of a compound(I), in which an o-hydroxyacetophenone of the general formula ##STR4##in which R, R¹ and R² have the above-mentioned meanings, is reacted witha glyoxylic acid derivative of the general formula

    OCH--COOZ                                                  (III),

in which Z represents a cation, in the presence of a basic compound and,if desired, the dicarboxylic acid obtained after acidification (acompound of the formula (I), wherein R³ represents hydrogen) isconverted in a manner which is in itself known into a correspondingester (a compound of the formula (I), wherein R³ represents anoptionally substituted alkyl, alkenyl, cycloalkyl, cycloalkenyl oraralkyl group).

It must be described as distinctly surprising that theo-hydroxyacetophenones of the formula (II) react with the glyoxylic acidderivatives of the formula (III) in a simple and controllable reactionto give the chromone derivatives of the formula (I) and that nochromanone compounds are formed. The discovery of the new reactionrepresents an enrichment of the art. It is of industrial interest thatthe new compounds can be used as plant protection agents.

If o-hydroxyacetophenone is reacted with the sodium salt of glyoxylicacid in the presence of pyrrolidine and the resulting dicarboxylic acidis then esterified with methanol, the course of the reaction can berepresented by the following equations: ##STR5##

The o-hydroxy-aryl-carbonyl compounds which can be used for the processaccording to the invention are known (see Beilstein, Handbuch derOrganischen Chemie (Handbook of Organic Chemistry), H8, page 85 etseq.). As examples there may be mentioned: o-hydroxyacetophenone,3-chloro-2-hydroxyacetophenone, 5-chloro-2-hydroxyacetophenone,3,5-dichloro-2-hydroxyacetophenone,3-methyl-5-chloro-2-hydroxyacetophenone, 2,4-dihydroxyacetophenone,2,5-dihydroxyacetophenone, 2,6-dihydroxyacetophenone,2,3-dihydroxyacetophenone, 2,4,6-trihydroxyacetophenone,4-pentyl-2,6-dihydroxyacetophenone, 4-heptyl-2,6-dihydroxyacetophenone,4-(1',1'-dimethylpentyl)-2,6-dihydroxyacetophenone,3,4-dimethoxy-6-methyl-2-hydroxyacetophenone,3,4,6-trimethyl-2-hydroxyacetophenone, 3-methoxy-2-hydroxyacetophenone,4-methoxy-2-hydroxyacetophenone, 5-methoxy-2-hydroxyacetophenone,6-methoxy-2-hydroxyacetophenone, 4-benzyloxy-2-hydroxyacetophenone,5-benzyloxy-2-hydroxyacetophenone, 4-phenoxy-2-hydroxyacetophenone,4-cyclohexyl-2-hydroxyacetophenone, 5-phenyl-2-hydroxyacetophenone,3-β-phenylethyl-2-hydroxyacetophenone,5-δ-phenylbutyl-2-hydroxyacetophenone,3,5-dibromo-2-hydroxyacetophenone, 4-ethoxy-2-hydroxyacetophenone,5-ethoxycarbonylethoxy-2-hydroxyacetophenone,4-methoxycarbonylmethoxy-2-hydroxyacetophenone,4-carboxymethyl-2-hydroxyacetophenone, 5-nitro-2-hydroxyacetophenone,3-cyano-2-hydroxyacetophenone, 4-trifluoromethyl-2-hydroxyacetophenone,5-trifluoromethyl-2-hydroxyacetophenone,3-trifluoromethyl-2-hydroxyacetophenone,3-methoxycarbonyl-2-hydroxyacetophenone,5-carboxy-2-hydroxyacetophenone, 5-dimethylamino-2-hydroxyacetophenone,4-N-piperidinyl-2 -hydroxyacetophenone, 3-phenoxy-2-hydroxyacetophenone,4-p-chlorophenoxy-2-hydroxyacetophenone,5-p-tolyl-2-hydroxyacetophenone, 1-hydroxy-2-acetylnaphthalene and2-hydroxy-1-acetylnaphthalene.

In addition, the gloxylic acid derivatives of the formula (III) arerequired as starting compounds. In the formula (III), Z preferablyrepresents an alkali metal cation, an equivalent of an alkaline earthmetal cation, an ammonium cation or a monoalkylammonium, dialkylammoniumor trialkylammonium cation.

The synthesis is carried out in the presence of a basic compound. Assuch, it is preferred to use secondary amines, such as open-chainamines, such as dimethylamine and diethylamine, and, more especially,cyclic amines such as pyrrolidine and also piperidine,N-methyl-piperazine and morpholine. The said compounds are generallyknown.

The process according to the invention can be carried out with orwithout a solvent. All solvents which are inert towards the startingcomponents and the end product can be used to carry out the process. Asexamples of solvents there may be mentioned: aliphatic or aromatichydrocarbons, such as petroleum ether, benzene, toluene or xylene;aliphatic or aromatic halohydrocarbons, such as carbon tetrachloride,chlorobenzene or dichlorobenzene; ethers, such as diethyl ether,tetrahydrofuran, dioxan or glycol dimethyl ether; amides, such asdimethylformamide, dimethylacetamide and N-methylpyrrolidone; esters,such as ethyl acetate; nitriles, such as acetonitrile and propionitrile;alcohols, such as methanol, ethanol and glycol monomethyl ether; water;and mixtures of these solvents.

The process according to the invention can be carried out at atemperature of about -30° C. to +150° C., preferably of about 20° to 80°C.

To carry out the process according to the invention, theo-hydroxycarbonyl compound (II) and the salt of the glyoxylic acid (III)are in general employed in stoichiometric amounts, that is to say in theratio of about 1:2. However, for the purpose of carrying out the processaccording to the invention it does not matter if a small excess of onecomponent, especially of the glyoxylic acid salt, is employed (forexample up to a molar ratio of about 1:2.5). The amount of the amineemployed is not critical. In general, about 0.05 to 1.5, preferablyabout 0.1 to 1, mole of the amine is used per mole of theo-hydroxycarbonyl compound. If the o-hydroxyacetophenones aresubstituted by groups with an acid reaction, such as, for example,carboxyl groups, it can be advantageous to neutralize the acid groups byan excess of the amine.

In general, the process according to the invention is carried out asfollows:

At the selected reaction temperature, the starting compounds aredissolved, if appropriate in a solvent, and the amine is added. As aresult of the exothermic reaction, the reaction temperature in generalrises so that further warming is not necessary. The reaction mixture isthen left to stand, without further warming, until completion of thereaction, but the reaction time can also be shortened by externalwarming. After completion of the reaction, the chromone derivative isisolated by dissolving the resulting salt in water and acidifying thissolution, for example with a mineral acid such as hydrochloric acid,sulphuric acid or phosphoric acid. The dicarboxylic acid compound of theformula (I), wherein R³ represents hydrogen, is thus obtained.

The esterification of the dicarboxylic acid obtained can be carried out,for example, in the usual manner by stirring the dicarboxylic acid withabout a 4-fold to 100-fold, preferably about 10-fold to 50-fold, molaramount of alcohol of the formula R³ -OH, adding an acid such asconcentrated sulphuric acid or saturating the mixture with hydrogenchloride gas, and warming the whole for a few hours at temperatures ofabout 60° to 120° C. It is also possible to add an at least twice themolar amount, relative to the dicarboxylic acid, of a dehydrating agent,such as an inorganic acid halide, for example thionyl chloride orphosphorus oxychloride, to the mixture of the dicarboxylic acid with thealcohol. Finally, it is also possible to react a salt of thedicarboxylic acid with at least twice the molar amount of an alkylhalide, in a solvent such as dimethylsulphoxide or dimethylformamide.

As examples of new chromonedicarboxylic acids and their esters there maybe mentioned: 2-carboxy-3-carboxymethylchromone,2-carboxy-3-carboxymethyl-6-chloro-chromone,2-carboxy-3-carboxymethyl-7-chloro-chromone,2-carboxy-3-carboxymethyl-8-chloro-chromone,2-carboxy-3-carboxymethyl-6,8-dichloro-chromone,2-carboxy-3-carboxymethyl-6-methylchromone,2-carboxy-3-carboxymethyl-7-methyl-chromone,2-carboxy-3-carboxymethyl-6-isobutyl-chromone,2-carboxy-3-carboxymethyl-7-ethyl-chromone,2-carboxy-3-carboxymethyl-6-sec.-butyl-chromone,2-carboxy-3-carboxymethyl-6-benzyl-chromone,2-carboxy-3-carboxymethyl-7-phenyl-chromone,2-carboxy-3-carboxymethyl-5-methoxy-chromone,2-carboxy-3-carboxymethyl-6-methoxy-chromone,2-carboxy-3-carboxymethyl-7-methoxy-chromone,2-carboxy-3-carboxymethyl-8-methoxy-chromone,2-carboxy-3-carboxymethyl-6-chloro-8-methylchromone,2-carboxy-3-carboxymethyl-6-pyrrolidinyl-chromone,2-carboxy-3-carboxymethyl-6-dimethylamino-chromone,2-carboxy-3-carboxymethyl-7,8-dimethoxy-chromone,2-carboxy-3-carboxymethyl-6,7-dimethoxy-chromone,2-carboxy-3-carboxymethyl-6-methoxycarbonyl-chromone,2-carboxy-3-carboxymethyl-8-carboxy-chromone,2-carboxy-3-carboxymethyl-7-cyano-chromone,2-carboxy-3-carboxymethyl-6-cyanochromone,2-carboxy-3-carboxymethyl-5,6,7-trimethylchromone,2-carboxy-3-carboxymethyl-5,6-benzo-chromone,2-carboxy-3-carboxymethyl-5,6-trimethylene-chromone,2-carboxy-3-carboxymethyl-5-methyl-6,8-dichloro-chromone,2-carbomethoxy-3-carbomethoxymethyl-chromone,2-carbomethoxy-3-carbomethoxymethyl-6-chloro-chromone,2-carbomethoxy-3-carbomethoxymethyl-7-chloro-chromone,2-carbomethoxy-3-carbomethoxymethyl-6,8-dichloro-chromone,2-carbomethoxy-3-carbomethoxymethyl-6-methyl-chromone,2-carbomethoxy-3-carbomethoxymethyl-7-methyl-chromone,2-carbomethoxy-3-carbomethoxymethyl-6-isobutyl-chromone,2-carbomethoxy-3-carbomethoxymethyl-6-cyclopentyl-chromone,2-carbomethoxy-3-carbomethoxymethyl-7-phenyl-chromone,2-carbomethoxy-3-carbomethoxymethyl-5-methoxy-chromone,2-carbomethoxy-3-carbomethoxymethyl-6-methoxy-chromone,2-carbomethoxy-3-carbomethoxymethyl-7-methoxy-chromone,2-carbomethoxy-3-carbomethoxymethyl-8-methoxy-chromone,2-carbomethoxy-3-carbomethoxymethyl-6-chloro-8-methylchromone,2-carbomethoxy-3-carbomethoxymethyl-7,8-dimethoxychromone,2-carbomethoxy-3-carbomethoxymethyl-6,7-dimethoxychromone,2-carbomethoxy-3-carbomethoxymethyl-8-carboxychromone,2-carbomethoxy-3-carbomethoxymethyl-6-cyanochromone,2-carbomethoxy-3-carbomethoxymethyl-5,6-benzochromone,2-carbomethoxy-3-carbomethoxymethyl-5-methyl-6,8-dichloro-chromone,2-carboethoxy-3-carbo-ethoxymethylchromone,2-carbopropoxy-3-carbopropoxymethylchromone,2-carbo-isopropoxy-3-carbo-isopropoxymethylchromone,2-carbobutoxy-3-carbobutoxymethylchromone,2-carbo-sec.-butoxy-3-carbo-sec.-butoxymethylchromone,2-carbo-isobutoxy-3-carbo-iso-butoxymethylchromone,2-carbo-tert.-butoxy-3-carbo-tert.-butoxymethylchromone,2-carbobenzyloxy-3-carbobenzyloxymethylchromone,2-carbophenethoxy-3-carbophenethoxymethylchromone,2-carbocyclopentyloxy-3-carbocyclopentyloxymethylchromone,2-carbocyclohexyloxy-3-carbocyclohexyloxymethylchromone,2-carboallyloxy-3-carboallyloxymethylchromone,2-carbo-p-chlorobenzyloxy-3-carbo-p-chlorobenzyloxymethylchromone,2-carbo-(2'-methoxy)ethoxy-3-carbo-(2'-methoxy)-ethoxymethylchromone and2-carbo(2'-bromo)-ethoxy-3-carbo-2'-(bromo)-ethoxymethylchromone.

The active compounds according to the invention exhibit a powerfulfungitoxic action. They do not damage crop plants in the concentrationsrequired for combating fungi. For these reasons, they are suitable foruse as plant protection agents for combating fungi. Fungitoxic agentsare employed in plant protection for combating Plasmodiophoromycetes,Oomycetes, Chytridiomycetes, Zygomycetes, Ascomycetes, Basidiomycetesand Deuteromycetes.

The active compounds according to the invention can be used againstparasitic fungi and bacteria which attack above-ground parts of plantsor attack the plants through the soil, as well as against seed-bornepathogens.

The good toleration by plants permits the active compounds to be usedagainst fungal plant diseases by treating the standing crop plant orindividual parts thereof or by treating the seed or even by treating theculture soil. The active compounds are particularly active againstcereal mildew.

The active compounds can be converted into the customary formulations,such as solutions, emulsions, wettable powders, suspensions, powders,dusting agents, foams, pastes, soluble powders, granules, aerosols,suspension-emulsion concentrates, seed-treatment powders, natural andsynthetic materials impregnated with active compound, very fine capsulesin polymeric substances, coating compositions for use on seed, andformulations used with burning equipment, such as fumigating cartridges,fumigating cans and fumigating coils, as well as ULV cold mist and warmmist formulations.

These formulations may be produced in known manner, for example bymixing the active compounds with extenders, that is to say liquid orliquefied gaseous or solid diluents or carriers, optionally with the useof surface-active agents, that is to say emulsifying agents and/ordispersing agents and/or foam-forming agents. In the case of the use ofwater as an extender, organic solvents can, for example, also be used asauxiliary solvents.

As liquid solvents diluents or carriers, especially solvents, there aresuitable in the main, aromatic hydrocarbons, such as xylene, toluene oralkyl naphthalenes, chlorinated aromatic or chlorinated aliphatichydrocarbons, such as chlorobenzenes, chloroethylenes or methylenechloride, aliphatic or alicyclic hydrocarbons, such as cyclohexane orparaffins, for example mineral oil fractions, alcohols, such as butanolor glycol as well as their ethers and esters, ketones, such as acetone,methyl ethyl ketone, methyl isobutyl ketone of cyclohexanone, orstrongly polar solvents, such as dimethylformamide anddimethylsulphoxide, as well as water.

By liquefied gaseous diluents or carriers are meant liquids which wouldbe gaseous at normal temperature and under normal pressure, for exampleaerosol propellants, such as halogenated hydrocarbons as well as butane,propane, nitrogen and carbon dioxide.

As solid carriers there may be used ground natural minerals, such askaolins, clays, talc, chalk, quartz, attapulgite, montmorillonite ordiatomaceous earth, and ground synthetic minerals, such ashighly-dispersed silicic acid, alumina and silicates. As solid carriersfor granules there may be used crushed and fractionated natural rockssuch as calcite, marble, pumice, sepiolite and dolomite, as well assynthetic granules of inorganic and organic meals, and granules oforganic material such as sawdust, coconut shells, corn cobs and tobaccostalks.

As emulsifying and/or foam-forming agents there may be used non-ionicand anionic emulsifiers, such as polyoxyethylene-fatty acid esters,polyoxyethylene-fatty alcohol ethers, for example alkylaryl polyglycolethers, alkyl sulphonates, alkyl sulphates, aryl sulphonates as well asalbumin hydrolysis products. Dispersing agents include, for example,lignin sulphite waste liquors and methylcellulose.

The formulations in general contain from 0.1 to 95 percent by weight ofactive compound, preferably from 0.5 to 90 percent.

The active compounds can be used as such, as their formulations or asthe use forms prepared therefrom by further dilution, such asready-to-use solutions, emulsions, suspensions, powders, pastes andgranules. They may be used in the customary manner, for example bywatering, spraying, atomizing, dusting, scattering, dry dressing, moistdressing, wet dressing, slurry dressing or encrusting.

The active compound content of the use forms prepared from theformulations of the types that are commercially available can varywithin wide ranges. The active compound concentration of the use formscan be from 0.0000001 to 100% by weight of active compound, preferablyfrom 0.01 to 10% by weight.

For dressing, amounts of active compound of 10 mg to 10 g, preferably100 mg to 3 g, are in general used per kilogram of seed. For thetreatment of soil, which can be carried out over the whole area, instrips or at points, active compound concentrations of 1 to 1,000 g ofactive compound per m³ of soil, preferably 10 to 200 g per m³, aregenerally employed at the locus of the expected action.

As already mentioned, the compounds according to the invention inhibitthe development of arthropods.

The present invention also provides fungicidal or arthropodicidalcompositions containing as active ingredient a compound of the presentinvention in admixture with a solid or liquefied gaseous diluent orcarrier or in admixture with a liquid diluent or carrier containing asurface-active agent.

The present invention also provides a method of combating fungi orarthropods which comprises applying to the fungi or arthropods, or to ahabitat thereof, a compound of the present invention alone or in theform of a composition containing as active ingredient a compound of thepresent invention in admixture with a diluent or carrier.

The present invention further provides crops protected from damage byfungi or arthropods by being grown in areas in which immediately priorto and/or during the time of the growing a compound of the presentinvention was applied alone or in admixture with a diluent or carrier.

It will be seen that the usual methods of providing a harvested crop maybe improved by the present invention.

The preparation of the novel compounds is shown in the followingillustrative examples:

EXAMPLE 1 ##STR6##

75 g (0.55 mol) of o-hydroxyacetophenone and 350 ml of water/ice werestirred with 60 ml of pyrrolidine. 250 g of sodium glyoxylate (hydrate,about 50% strength; 1.1 mol) were added to the clear solution and themixture was stirred further, without cooling. After a few hours, thesalt had given an almost clear solution; later, a part of the endproduct separated out as the disodium salt. After 5 days, about 600 mlof water were added, stirring was continued until an almost clearsolution resulted, and concentrated hydrochloric acid was added to thefiltrate until a pH value of 1 was reached. The precipitate whichseparated out was filtered off after 1 day, and dried. Yield: 125 g of2-carboxy-3-carboxymethyl-chromone, of melting point 240°-242° C.,representing 92% of theory.

EXAMPLE 1a

The procedure described in Example 1 was followed, but after mixing thestarting materials the batch was warmed for 30 minutes to 95° C. Workingup gave 112 g of 2-carboxy-3-carboxymethyl-chromone, representing 82% oftheory.

EXAMPLE 2 ##STR7##

63 g of 4-phenyl-2-hydroxyacetophenone, 700 ml of isopropanol and 110 gof a 50% strength solution of glyoxylic acid in water were stirred and63 g of pyrrolidine were added at a temperature below 0° C. After 6days, the resulting solution was diluted with 1 liter of water andacidified. Yield: 22 g of 2-carboxy-3-carboxymethyl-7-phenyl-chromone ofmelting point 219°-221° C.

EXAMPLE 3 (Esterification reaction) ##STR8##

220 g of 2-carboxy-3-carboxymethyl-chromone (prepared according toExample 1) were stirred into 2 liters of methanol, hydrogen chloride gaswas introduced until saturation was reached and the mixture was warmedat the same time, until the reflux temperature was reached. After 8hours, the mixture as allowed to cool and the product was filtered off.196 g of 2-carbomethoxy-3-carbomethoxymethyl-chromone of melting point105° C. were obtained.

EXAMPLE 3a (Esterification reaction; compare Example 3)

15 g of 2-carboxy-3-carboxymethyl-chromone were stirred into 60 ml ofmethanol, and 15 ml of thionyl chloride were added in the course ofabout 10 minutes, while keeping the temperature below 35° C. The mixturewas then heated to 60° C. over the course of 2 hours, and was allowed tocool, and the product was filtered off. 13.5 g of the same product asdescribed in Example 3 were obtained.

EXAMPLE 4 (Esterification reaction) ##STR9##

25 g of 2-carboxy-3-carboxymethyl-chromone were dissolved in 30 ml ofdimethylsulphoxide, and 30 ml of triethylamine and 30 g of benzylchloride were added successively. After 24 hours the mixture was pouredonto ice water and was extracted by shaking with chloroform, and thechloroform layer was washed with 100 ml of 2-normal sodium hydroxidesolution and then with water. After drying and concentrating, a residuewas obtained, which was recrystallized from ether. The yield was 17 g of2-benzyloxycarbonyl-3-benzyloxycarbonylmethyl-chromone of melting point82°-84° C.

The following compounds of the general formula ##STR10## could beprepared in a similar manner to that described in Examples 1 to 4.

                  TABLE 1                                                         ______________________________________                                        Com-                               Yield Melting                              pound                              % of  point                                No.   R         R.sup.1   R.sup.2                                                                           R.sup.3                                                                            theory                                                                              (°C.)                         ______________________________________                                        5     6-Cl      H         H   H    77    219-221                              6     7-Cl      H         H   H    84    150-152                              7     6-Cl      8-Cl      H   H    66    230-232                              8     6-Cl      8-CH.sub.3                                                                              H   H    74    170-172                              9     6-CH.sub.3 O                                                                            H         H   H    77    225-227                              10    7-CH.sub.3 O                                                                            H         H   H    61    239-241                              11    7-CH.sub.3 O                                                                            8-CH.sub.3 O                                                                            H   H    80    230-232                              12    6-CH.sub.3                                                                              H         H   H    83    204-206                              13    7-CH.sub.3                                                                              H         H   H    64    147-148                              14    5,6-CH═CH--CH═CH                                                                      H     H    51    decomposes                                                                    above 150                              15    H         H         H   C.sub.2 H.sub.5                                                                    60    63-65                                16    7-CH.sub.3 O                                                                            H         H   CH.sub.3                                                                           87    118-120                              17    6-Cl      8-Cl      H   CH.sub.3                                                                           90    139-141                              18    6-Cl      H         H   CH.sub.3                                                                           88    169-171                              19    7-Cl      H         H   CH.sub.3                                                                           87    147-148                              20    7-CH.sub.3                                                                              H         H   CH.sub. 3                                                                          70    123-125                              21    6-Cl      8-CH.sub.3                                                                              H   CH.sub.3                                                                           65    138-141                              22    7-CH.sub.3 O                                                                            8-CH.sub.3 O                                                                            H   CH.sub.3                                                                           63    163-165                              23    6-CH.sub.3                                                                              H         H   CH.sub.3                                                                           51    155-157                              ______________________________________                                    

The example given below illustrates the arthropodmetamorphosis-inhibiting action of the compounds according to theinvention, without intending a limitation in respect of the breadth ofaction of these compounds. In the experiments, the morphologicalchanges, such as half-pupated insects, incompletely slipped larvae orcaterpillars, defective wings and pupal cuticula of imagines, as well asthe mortality, were assessed over the entire stated development of thetest insects. The sum of the morphological malformations and of thedestruction during development was assessed.

EXAMPLE 5 Development-inhibiting action/ingestion test

Test insects:

Plutella maculipennis (caterpillars in the 4th state of development, 20specimens)

Phaedon cochleariae (larvae in the 4th stage of development, 20specimens)

Feed plants: Cabbage plants (Brassica oleracea)

Solvent: 4 parts by weight of acetone

Emulsifier: 1 part by weight of alkylaryl polyglycol ether

To produce a suitable preparation of active compound, 2 parts by weightof active compound were mixed with the stated amounts of solvent and ofemulsifier and with sufficient water to give a 1% strength mixture,which was diluted with water to the desired concentration.

The test animals were fed with leaves of the feed plants, which wereprovided with a uniform spray covering of the active compound mixture ofthe desired concentrations, so that the prescribed amounts of activecompound in ppm (parts per million) were obtained on the leaves, untilthe imago developed.

As a control, leaves provided only with solvent and emulsifier of theprescribed concentration were used as the feed.

Evaluation of the experiments showed that, in particular, compounds 3, 5and 10 according to the invention were superior to a known comparisonformulation to a known comparison formulation(2,2-dimethyl-6-methoxy-benzopyran).

The fungicidal activity of the compounds of this invention isillustrated by the following example wherein the compounds according tothe present invention are each identified by the number (given inbrackets) from the preparative examples hereinabove.

The known comparison compound is identified as follows: ##STR11##

EXAMPLE 6 Shoot treatment test/powdery mildew of cereals(leaf-destructive mycosis)/protective

To produce a suitable preparation of active compound, 0.25 part byweight of active compound was taken up in 25 parts by weight ofdimethylformamide and 0.06 part by weight of alkylaryl polyglycol ether;975 parts by weight of water were then added. The concentrate wasdiluted with water to the desired final concentration of the sprayliquor.

To test for protective activity, single-leaved young barley plants ofthe Amsel variety were sprayed with the preparation of active compounduntil dew-moist. After drying, the barley plants were dusted with sporesof Erysiphe graminis var. hordei.

After 6 days' dwell time of the plants at a temperature of 21-22 deg.C.and 80-90% atmospheric humidity the occurrence of mildew pustules on theplants was evaluated. The degree of infection was expressed as apercentage of the infection of the untreated control plants. 0% denotedno infection and 100% denoted the same degree of infection as in thecase of the untreated control. The more active the compound, the lowerwas the degree of mildew infection.

The active compounds, active compound concentrations in the spray liquorand degrees of infection can be seen from the table which follows:

                  TABLE 2                                                         ______________________________________                                        Shoot treatment test/powdery mildew of                                        cereals/protective                                                                         Active compound                                                               concentration                                                                              Infection in                                                     in the spray % of the un-                                        Active       liquor in % by                                                                             treated con-                                        compounds    weight       trol                                                ______________________________________                                        untreated    --           100.0                                               (A)          0.025        100.0                                               (3)          0.025        0.0                                                 (16)         0.025        20.0                                                (18)         0.025        38.5                                                ______________________________________                                    

It will be appreciated that the instant specification and examples areset forth by way of illustration and not limitation, and that variousmodifications and changes may be made without departing from the spiritand scope of the present invention.

What we claim is:
 1. A process for the preparation of a compound of theformula ##STR12## in which R, R¹ and R² each independently is hydrogen,an alkyl, alkenyl, cycloalkyl, cycloalkenyl, aralkyl or an aryl group,halogen, hydroxyl, cyano or an alkoxy, aryloxy, aralkoxy, alkoxycarbonylor dialkylamino group, orR and R¹ together with two carbon atoms of thebenzene ring system, form a carbocyclic 5-membered or 6-membered, furan,thiophene, dihydrothiophene, pyrane, dihydropyrane, pyridine ordioxolene ring, and Z is a cation,comprising reacting ano-hydroxyacetophenone of the formula ##STR13## with a glyoxylic acidderivative of the formula

    OCH-COOZ

in which Z is a cation, in the presence of a secondary amine.
 2. Aprocess according to claim 1, in which the secondary amine ispyrrolidine, piperidine, N-methyl-piperazine, morpholine, dimethylamineor diethylamine.
 3. A pocess according to claim 1 in which the reactionis carried out at from about -30° to +150° C.
 4. A process according toclaim 1, in which the reaction is effected in the presence of an inertorganic solvent or water.
 5. A process according to claim 1, in which Zis an alkali metal cation, an equivalent of an alkaline earth metal, anammonium cation or a monoalkylammonium, dialkylammonium ortrialkylammonium cation.
 6. A process according to claim 1, in whichabout 2 to 2.5 moles of the glyoxylic acid derivative are employed permole of the o-hydroxyacetophenone.
 7. A process according to claim 1, inwhich about 0.05 to 1.5 moles of the secondary amine are used per moleof the o-hydroxyacetophenone.
 8. A process according to claim 1,including the further steps of acidifying the reaction mass thereby toform the dicarboxylic acid wherein both Z's are converted to hydrogen.9. A process according to claim 8, including the further step ofreacting the dicarboxylic acid with about 4 to 100 times its molaramount of an alcohol of the formula

    R.sup.3 OH

wherein R³ is alkyl, alkenyl, cycloalkyl, cycloalkenyl or aralkyl, inthe presence of an acid to replace both Z's by R³.
 10. A processaccording to claim 9, wherein R, R¹ and R² are hydrogen and R³ is CH₃.11. A process according to claim 9, wherein R and R¹ are hydrogen, R² is7-OCH₃, and R³ is CH₃.
 12. A process according to claim 9, wherein R andR¹ are hydrogen, R² is 6-Cl, and R³ is CH₃.